Increased diameter arthritic golf club grips

ABSTRACT

A golf club grip system having grips that have grip diameters ranging from 1.0 inches (25.4 mm) to 1.2 inches (30.5 mm). Additionally, each golf club grip may include an outer wrap and an inner layer. The outer wrap is substantially thinner than the inner layer and consists predominantly of polyurethane and felt. Specifically, in one exemplary embodiment, the outer wrap consists of two separate layers of polyurethane, a layer of felt, and two thin strips of adhesive tape. By utilizing these materials, the outer wrap provides a high traction, i.e., slip resistant, surface with improved shock and vibration dampening characteristics. Additionally, by utilizing the combination of the outer wrap and the inner layer, the grip provides shock absorption with substantially increased resistant to torsional forces.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under Title 35, U.S.C. §119(e) ofU.S. Provisional Patent Application Ser. No. 61/049,840, entitledINCREASED DIAMETER ARTHRITIC GOLF CLUB GRIPS, filed on May 2, 2008, thedisclosure of which is expressly incorporated by reference herein.

BACKGROUND

1. Field of the Invention

The present invention relates to golf clubs and, particularly, to golfgrips for use in conjunction with golf clubs.

2. Description of the Related Art

In a normal, healthy hand, each of the finger joints of the hand arecapable of flexing approximately 90 degrees relative to one another toallow the hand and the corresponding fingers to wrap around an object.Additionally, this allows for the hand to exert substantial compressiveforces against the object to grasp and move the same. As a result, aperson having normal, healthy hands is capable of efficiently graspingstandard diameter golf club grips in order to swing a golf club.

However, when a person develops osteoarthritis in the hands and/orfingers, osteoarthritic changes of the finger joints may occur andinflammation and pain in the finger joints may result. This may lead toswelling and the formation of heterotopic bone within the finger joints,which may result in the joints of the fingers having a reduced range ofmotion. For example, in some people, the reduction in range of motionmay be ten to fifty percent of the range of motion of a normal, healthyhand. This reduces the ability of the individual to wrap their handaround an object having a small diameter, such as a golf club grip, andto exert a substantial compressive force on the same. Moreover, due tothe inflammation and pain in the joint caused by the osteoarthritis, theindividual may opt to utilize their hands to grasp objects lessfrequently, causing atrophy of the muscles that further reduces thegrasping strength of the individual.

While golf club grips having slightly larger diameters than a standardgrip have been introduced for arthritic golfers, the increased diameterof these grips results in the golfer using a grip that has a diameterthat is larger than the ideal golf club grip diameter for theindividual. As a result, the individual is hampered in his or herability to achieve the desired combination of maximum club head impactspeed and optimal club head rotation rate through the hitting area.Specifically, arthritic golf club grips are made of substantially softermaterials than are utilized in standard grips to allow the arthriticgrip to more effectively absorb shock and vibration generated duringball striking and, correspondingly, reduce the pain and/or discomfortthat a golfer may experience when hitting a golf ball. However, the useof softer materials in the construction of an arthritic golf club gripresults in the grip experiencing greater torsion, i.e., being lessresistant to rotational forces, during a golf swing. This results in thearthritic golf club grip experiencing excessive twisting between thegolfer's hands and shaft of the golf club during a golf swing, which maycause a loss of directional control during the golf shot.

In addition to the problems identified above, arthritic golf club gripsare also intended to be used in conjunction with traditional methods ofswinging and gripping a golf club, such as the Vardon gripping method.Utilizing the Vardon gripping method, as shown generally in FIGS. 1-3,upper hand 10 is wrapped around grip 12 of golf shaft 14 with thumb 16of upper hand 10 placed so as to rest on top portion 18 of grip 12. Asshown in FIG. 2, lower hand 20 is then wrapped around grip 12 in amanner in which it encompasses thumb 16 of upper hand 10, as well asgrip 12. Currently, there are three traditionally accepted grippingmethods and all three gripping methods require thumb 16 of upper hand 10to be positioned on top portion 18 of grip 12 with lower hand 20encompassing both thumb 16 and grip 12. Specifically, the Vardonover-lapping technique, shown in FIGS. 1-4, requires pinky finger 22(FIG. 4) of lower hand 20 to rest on top of index finger 24 (FIG. 4) ofupper hand 10. The Interlocking technique, shown in FIG. 5, requiresthat pinky finger 22 of lower hand 20 is positioned between index finger24 and pointer finger 26 of upper hand 10. The Ten-Finger technique,shown in FIG. 6, requires pinky finger 22 of lower hand 20 to wrapdirectly onto grip 12 so that the lateral aspect of pinky finger 22 oflower hand 20 rests against the medial aspect of pointer finger 26 ofupper hand 10.

Currently, these three gripping methods are the industry standard forhand placement on a golf club. In fact, the use of standard size golfclub grips in conjunction with the use of these three methods forgripping the golf grip has performed extremely well for professional andlow handicapped golfers. However, for the remaining majority of golfers,including arthritic golfers, this combination of grip size and grippingtechnique has performed poorly and has led to a great deal offrustration.

SUMMARY

In one exemplary embodiment, the present invention provides a golf clubgrip system having grips that have grip diameters ranging from 1.0inches to 1.2 inches. Each of the grips have a substantially cylindricalbody that defines an open end for receipt of a golf club shaft, a closedor cap end, and a gripping surface. Additionally, each grip may includean inner layer, which defines a substantially cylindrical body that hasan open end for receipt of a golf club shaft and a closed or cap end,and an outer wrap, which defines a gripping surface and surrounds atleast a portion of the inner layer. In one exemplary embodiment, theouter wrap is spiral wrapped around the inner layer in a known manner toform the golf club grip. The outer wrap is substantially thinner thanthe inner layer and consists predominantly of polyurethane and a naturalfiber felt layer. Specifically, in one exemplary embodiment, the outerwrap consists of two separate layers of polyurethane, a layer of felt,and two thin adhesive layers. By utilizing these materials, the outerwrap provides a high traction, i.e., slip resistant, surface withimproved shock and vibration dampening characteristics.

As indicated above, to form a completed golf club grip, the outer wrapis secured to a thicker inner layer by spiral wrapping the outer warparound the inner layer in a known manner. In one exemplary embodiment,the thicker inner layer consists of a dense, torsion resistant syntheticrubber. Advantageously, the inner layer utilizes materials that providea torsion resistant foundation for the outer wrap that minimizes thetorsion between the shaft of the golf club and the golfer's hand whenthe golf club is in use.

By utilizing the oversized grip system of the present invention,arthritic golfers, with their associated reduced finger flexion andstrength can comfortably grasp the larger diameter grips and swing thegolf club without any reduction of the maximum club head velocity orclub head rotational rate. As a result, this grip system provides equalor superior protection from shock and vibration without the undesirableincrease in grip torsion of previous arthritic golf grips.

In another exemplary embodiment, the present invention provides a golfclub gripping method that allows a golfer to easily convert from thestandard gripping method used with standard sized golf grips to the newgripping method used with oversized diameter golf grips made inaccordance with the present invention. Advantageously, the use of thegolf club grip method of the present invention in conjunction withoversized grips provides an arthritic golfer with a golf grip that iscapable of substantially improving their ability to hit a golf ball,resulting in an improved golf game.

In one form thereof, the present invention provides a golf club gripsystem, including a golf club grip having an inner layer and an outerwrap. The inner layer is formed as a substantially cylindrical bodyhaving an open end for receipt of a golf club shaft and a cap end. Theouter wrap surrounds at least a portion of the inner layer and defines agripping surface. The golf club grip has a grip diameter prior toinstallation on a golf club shaft that is defined by the grippingsurface and has a grip wall thickness extending radially from an innersurface of the inner layer to the gripping surface. Both of the gripdiameter and the grip wall thickness are measured at a point about 158millimeters from a proximal end of each of the plurality of golf clubgrips defined by the cap end of each of the plurality of golf clubgrips, with the grip diameter being at least 25.4 millimeters and nomore than 30.5 millimeters. Additionally, the golf club grip has adegree of torsion of at least 5 degrees and no more than 20 degrees, anelastic deformation under 5 pounds of vertical compressive force of atleast 1.0 millimeters and no more than 2.0 millimeters, and an elasticdeformation under 15 pounds of vertical compressive force of at least1.5 millimeters and no more than 3.0 millimeters.

In another form thereof, the present invention provides a golf club gripsystem, including a plurality of golf club grips, each of the pluralityof golf club grips including an inner layer forming a substantiallycylindrical body having an open end for receipt of a golf club shaft anda cap end. The inner layer also has an inner layer thickness measuredprior to installation on a golf club shaft. The outer wrap surrounds atleast a portion of the inner layer and defines a gripping surface. Theouter wrap also has an outer wrap thickness measured prior toinstallation on a golf club shaft. The outer wrap includes a firstpolymer layer secured to a first side of a felt layer, a first adhesivepositioned on a second side of the felt layer, and a second polymerlayer secured to the second side of the felt layer by the adhesive, withthe inner layer thickness being at least 2.3 times greater than theouter wrap thickness and no more than 3.1 times greater than the outerwrap thickness when measured at a distance of about 158 millimeters froma proximal end of each of the plurality of golf club grips defined bythe cap end of each of the plurality of golf club grips.

In yet another form thereof, the present invention provides a golf clubgrip system, including a plurality of golf club grips, with each of theplurality of golf club grips having an inner layer and an outer wrap.The inner layer forms a substantially cylindrical body having an openend for receipt of a golf club shaft and a cap end. The outer wrapsurrounds at least a portion of the inner layer and defines a grippingsurface, with each of the plurality of golf club grips having a gripdiameter prior to installation on a golf club shaft defined by thegripping surface and a grip wall thickness extending radially from aninner surface of the inner layer to the gripping surface. Both of thegrip diameter and the grip wall thickness are measured at a distance ofabout 158 millimeters from a proximal end of each of the plurality ofgolf club grips defined by the cap end of each of the plurality of golfclub grips. The grip diameter being at least 3.8 times greater than thegrip wall thickness and no more than 4.7 times greater than the gripwall thickness.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention itself will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 is a perspective view of an upper hand positioned on a golf gripin accordance with the Vardon gripping method, the Interlocking grippingmethod, and the Ten-Finger gripping method;

FIG. 2 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the Vardon gripping method;

FIG. 3 is another perspective view of the pair of hands of FIG. 2positioned on a golf grip in accordance with the Vardon gripping method;

FIG. 4 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the Vardon gripping method;

FIG. 5 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the Interlocking gripping method;

FIG. 6 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the Ten-Finger gripping method;

FIG. 7 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the Vardon gripping method;

FIG. 8 is a depiction of a golf club making contact with a golf ball ina substantially squared condition;

FIG. 9 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the baseball style gripping method;

FIG. 10 is another perspective view of a pair of hands positioned on agolf grip in accordance with the baseball style gripping method;

FIG. 11 is a perspective view of a pair of hands positioned on a golfgrip in accordance with a partial baseball style/partial traditionalgripping method;

FIG. 12 is a depiction of a golf club making contact with a golf ball inan over rotated condition;

FIG. 13 is a perspective view of a pair of hands positioned on a golfgrip in accordance with the Diagonal Rotational Power gripping method;

FIG. 14 is another perspective view of a pair of hands positioned on agolf grip in accordance with the Diagonal Rotational Power grippingmethod;

FIG. 15 is a longitudinal cross-sectional view of a golf grip of thepresent invention taken along plane P in FIG. 17;

FIG. 16 is a perspective, partial cross-sectional view of the golf gripof the present invention depicting the individual layers forming thegolf grip;

FIG. 17 is a perspective view of a golf grip of the present inventiondepicting plane P extending therethrough;

FIG. 18 is a graph of golfer satisfactions scores correlated to golfgrip diameter;

FIG. 19 is a graph of golfer satisfactions scores correlated to golfer'swearing a small men's golf glove size;

FIG. 20 is a graph of golfer satisfactions scores correlated to golfer'swearing a medium men's golf glove size;

FIG. 21 is a graph of golfer satisfactions scores correlated to golfer'swearing a large men's golf glove size;

FIG. 22 is a graph of golfer satisfactions scores correlated to golfer'swearing a extra-large men's golf glove size:

FIG. 23 is a graph of golfer satisfactions scores correlated to golfer'swearing a extra-extra-large men's golf glove size;

FIG. 24 is a graph of golfer satisfactions scores correlated to themen's golf glove size of the individual golfer;

FIG. 25 is a graph of golfer satisfactions scores correlated to golfer'srecommended golf grip size, a size one greater than the recommendedsize, and a size one lower than the recommended size;

FIG. 26 is a graph of golfer satisfactions scores correlated to golfersusing the baseball style gripping method and the Diagonal RotationalPower gripping method;

FIG. 27 is a partial plan view of the testing apparatus for elasticdeformation testing;

FIG. 28-31 are partial perspective views of the testing apparatus forelastic deformation testing;

FIG. 32 is a partial plan view of the testing apparatus for degree oftorsion testing;

FIGS. 33-35 are perspective views of the testing apparatus for degree oftorsion testing;

FIG. 36 is another partial plan view of the testing apparatus for degreeof torsion testing; and

FIGS. 37-42 are additional perspective views of the testing apparatusfor degree of torsion testing.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate preferred embodiments of the invention and suchexemplifications are not to be construed as limiting the scope of theinvention in any manner.

DETAILED DESCRIPTION

The present golf club grip system allows golfers to consistently rotatethe head of a golf club during the golf swing at the desired rate andhas characteristics sufficient for use with an arthritic hand. Forexample, in order for the grip to be beneficial for an arthritic golfer,the grip diameter must be large enough to allow the arthritic hand toadequately grasp and hold the golf club during a swinging action, whilethe circumference of the grip remains small enough that the golfer canadequately wrap their fingers around the grip to secure the golf clubduring the swinging action. Absent an indication to the contrary, asused herein, “grip diameter” and “total grip diameter” refer to thediameter of a cross-section of a golf club grip measured at a distanceof about 158 mm from the proximal end of the golf grip defined by capend 11, shown in FIG. 16. While cap end 11 is described and depictedherein as being an integral component of inner layer 110, describedbelow, cap end 11 may be a separate component that is secured to theinner layer during manufacture, a series of additional components thatcooperate to define cap end 11, or cap end 11 may secured to a differentportion of the golf club grip. However, regardless of its configuration,cap end 11 defines the proximal end of the grip, i.e., the end of thegrip that is opposite the club head and closest to the golfer.

Additionally, depending on the context in which the phrase “gripdiameter” or “total grip diameter” is used, it may refer to the diameterof a cross-section of the golf grip taken perpendicular to thelongitudinal axis of the grip and measured at a distance of about 158 mmfrom the proximal end of the grip defined by cap end 11 either before orafter the grip has been installed onto a standard golf club shaft havinga golf shaft diameter of substantially 0.60 inches. Similarly, absent anindication to the contrary, as used herein, “golf shaft diameter” is thecross-sectional diameter of a golf club shaft taken in a planetransverse to the longitudinal axis of the golf club shaft and at adistance of about 158 mm from the proximal end, i.e., the end oppositethe club head and closest to the golfer, of the golf shaft.

In making a golf shot, it is desirable to achieve the optimal club headrotation rate during rotational acceleration of the golf club, i.e. therotation rate that allows the golfer to accelerate the club head to themaximum impact velocity that will still allow the golfer to maintainexcellent control of the club head impact position and will provide thegolfer with the maximum amount of golf shot directional control. Thetotal club head velocity that is imparted to a golf ball is the sum ofthe linear acceleration of the club head that is achieved bystraightening the angle formed by the golf club shaft and the leadingarm of the golfer and the rotational acceleration of the club head alonga circular arc in the direction of the target. Specifically, during agolf shot, the head of the golf club is rotated through an approximate30 degree arc from 6 inches before impact to 6 inches after impact.i.e., the impact area. This arc of motion equates to an average clubhead rotation rate of 2.5 degrees per inch as the club head travelsthrough the impact area. The club head rotation rate through the impactarea of 2.5 degrees per inch is considered to be the optimal club headrotation rate and has been measured and confirmed by careful analysis ofthe golf swing of many of the top professional golfers of the world. Incontrast, if the golf head is rotated too slowly or too quickly throughthe impact area, the club face will contact the ball in an openposition, i.e., an under-rotated position, or a closed position, i.e. anover-rotated position, respectively, and will launch the ball in adirection that is off the intended target line with an excess of sidespin being transferred to the ball.

In order to consistently achieve the desired club head rotation rate, itmay be desirable to maintain a proper distance between the axis of thegolf shaft and the central axis of the wrist of the golfer's lower hand.Specifically, referring to FIG. 7, with lower hand 20 of the golferresting on golf grip 12, the lower hand must be rotated in the directionof the target during the golf swing in order to generate the optimalclub head rotation rate. Thus, a moment arm having a distance D iscreated between the central axis of the wrist of the golfer's lower handCA and the longitudinal axis of the golf shaft LAGS that acts as acantilever arm and affects the efficiency with which the muscles of thelower arm and hand are utilized to transfer rotational force to the golfclub and golf head. By insuring that a proper distance D is establishedbetween the axis of the golf shaft LAGS and the central axis of thewrist of the golfer's lower hand CA when the golfer's lower hand isplaced on the grip, an average club head rotation rate substantiallysimilar to the optimal club head rotation may be more consistentlyachieved.

In order to achieve the proper distance D between the longitudinal axisof the golf shaft LAGS and the central axis of the wrist of the golfer'slower hand CA, a standard golf club grip has an average grip diameter ofapproximately 21 mm, i.e., 0.827 inches, and is intended to be used withone of the three traditional gripping methods, which are described indetail above. As indicated above, all of these gripping methods requirethat the thumb of the golfer's upper hand is placed centrally on the topportion of the grip or on the top of the grip on the portion furthestaway from the target. The fingers of the lower hand are then placedaround the grip in a manner so that the lower hand encompasses both thegrip and the thumb of the upper hand. The diameter and the resultantcircumference that is created by the grip and the thumb of the upperhand determine the distance D that is established between thelongitudinal axis of the golf shaft LAGS and the central axis of thewrist of the lower hand CA. Several sizes of standard golf grips arecommonly available, varying from − 1/32 inches to −⅛ inches, toaccommodate variations in golfers' hand sizes while still establishingthe proper distance D between the longitudinal axis of the golf shaftLAGS and the center axis of the wrist of the golfer's lower hand CA.

However, if the grip diameter is increased to a size that is larger thanthe optimal grip diameter for a particular golfer, which is often thecase when an arthritic golfer utilizes an oversized grip, the distance Destablished between the longitudinal axis of the golf shaft LAGS and thecenter of the wrist of the golfer's lower hand CA will be decreased,i.e., a shorter moment arm will be formed, and the rotational force thatneeds to be applied to the golf club by the golfer's lower hand will besignificantly increased. This increase in the rotational force that mustbe applied to the golf club by the golfer during the swing may result inthe golfer being unable to consistently produce the force necessary toachieve both the maximum club head velocity and the optimal club headrotation rate, which are necessary to produce long, straight golf shots.

Additionally, if the grip diameter is decreased to a size that issmaller than the optimal grip diameter for a particular golfer, thedistance D between the longitudinal axis of the golf shaft LAGS and thecenter axis of the wrist of the lower hand CA will be increased, i.e., alonger moment arm will be created. This increased distance D willsignificantly reduce the force that must be applied by the lower handand fingers to rotate the club head properly through the impact area,but will dramatically increase the club head rotation rate to a speedfar greater than the optimal club head rate of rotation of 2.5 degreesper inch through the impact area. This increase in the club headrotation rate will make consistent and solid contact with the golf ballmuch more difficult. This is caused by the club head being perpendicularto the target line for a much shorter period of time. As a result, golfshot directional control will become significantly more difficult.

In order to develop an oversized grip system that has grip sizes thatestablish the proper distance D between the longitudinal axis of thegolf shaft LAGS and the center of the wrist of the golfer's lower handCA, testing was initiated, as set forth in Example 1 below. Based onthis testing, it was determined that oversized grips with grip diametersranging from about 1.00 inch (25.4 mm) to about 1.20 inches (30.48 mm)resulted in the best golf shots. Additionally, it was found that golferswith larger than average hand sizes produced their best results withgrips having larger diameters, while golfers with smaller than averagehand sizes, produced their best results with grips havingcorrespondingly smaller diameters. Thus, a grip size recommendationchart, as shown forth in Table 1 below, was created to correlatestandard golf glove sizes to oversized grip diameters.

TABLE 1 Grip Size Recommendation Chart Golf Glove Size Grip Diameter(inches) Men's Small 1.04 Men's Medium 1.07 Men's Large 1.10 Men'sX-Large 1.13 Men's XX-Large 1.16

Utilizing the grip size recommendation chart of Table 1, a second seriesof tests were performed in which the grip diameters of the oversizedgrips were limited to between about 1.04 inches (26.42 mm) and about1.16 inches (29.46 mm). Additionally, the golfers were matched to theappropriately sized oversized grips based on their golf glove size asdetermined by the grip size recommendation chart of Table 1. As setforth in detail below in Example 2, when using a properly matched grip,golfers were able to produce golf shots of better quality when comparedto the golf shots resulting using their original grips. Specifically, itwas found that golfers utilizing their recommended grip size ofoversized grips had golfer satisfaction scores that were substantiallyhigher than the golfer satisfaction scores of golfers using oversizedgrips either one grip size smaller than or one grip size larger thantheir recommended grip size. As used herein, “golfer satisfaction score”is a subjective score assigned by the individual golfer to each golfshot immediately after each golf shot is taken. As shown in Table 2below, each golfer satisfaction score is based on a 100 point GolferSatisfaction Scale having one point increments, with 100 pointsindicating that the golfer thought that the shot was excellent and 0points indicating that the ball did not move. The testing indicated thatthe use of the properly sized oversized grip provided more effectiveclub head rotation, which was confirmed by high speed photography andvideotape. Thus, when executed properly, the club face of a golferutilizing properly fitted oversized grips arrives at impact with thegolf ball in a square position in relation to the target, as shown inFIG. 8.

TABLE 2 Golfer Satisfaction Scale Assessed Golf Shot Quality AssessedPoints Excellent 100 Good 80 Acceptable 60 Poor 40 Very Poor 20 Ball DidNot Move 0

During the testing described above and in detail in Examples 1 and 2below, it was noticed that some golfers would utilize a baseball-stylemethod of gripping the oversized grip, as shown in FIGS. 9 and 10. Inthe baseball style method of gripping a golf grip, a golfer places theirhands around the golf grip in a similar fashion as one would grasp abaseball bat. Referring to FIGS. 9 and 10, the fingers and palms of bothupper and lower hands 10, 20 encircle golf grip 12 with the thumbs ofboth hands 10, 20 wrapped around grip 12 and overlapping the pointerfingers of their respective hand 10, 20. Grip 12 is oriented in hands10, 20 so that the long axis of the golf shaft LAGS runs perpendicularto the long axis of the fingers LAF. As a result, this grasping methodpositions the wrist of the lower hand in an excessively bent orexcessively arched position both at address and at the time of impact.As a result, the golfer would intermittently deliver the club face atimpact so that it struck the ball in a slightly over-rotated position,as shown in FIG. 12. This causes the golfer to produce a pulled orhooked golf shot, i.e., a shot that curves to the left or right,respectively.

Alternatively, other golfers that participated in the testing wouldgrasp the oversized grip with one of the traditional gripping methods,as shown in FIGS. 1-6. To reduce or eliminate the occurrence of aover-rotated club face at the time of impact, and its subsequentnegative affects on the golf shot, research was begun to develop a new,more effective method of grasping and utilizing an oversized golf grip.This new method of gripping an oversized golf grip has been named theDiagonal Rotational Power (“DRP”) method of gripping a golf club and,when used in conjunction with oversized grips, helps to ensure that theproper distance is established between the axis of the golf shaft LAGSand the center of the wrist of the lower hand CA, as discussed in detailabove with reference to FIG. 7.

In contrast to the baseball style gripping method of FIGS. 9 and 10, byutilizing the DRP method of gripping an oversized golf club grip, asshown in FIGS. 13 and 14, the golfer places their hands 10, 20 aroundgrip 12 on golf shaft 14 so that the fingers and palms encircle thegrip. The thumbs of both hands 10, 20 are also wrapped around the grip,in a somewhat similar manner to the thumb placement utilized in thebaseball style gripping method. However, as shown in FIG. 13, whenutilizing the DRP method, the grip is oriented relative to the golfer'shands 10, 20 so that the long axis of the golf shaft LAGS runs at adiagonal angle to a long axis of the fingers LAF of lower hand 20. Thethumb and index Finger of lower hand 20 are positioned so that the baseand medial aspect of the thumb runs parallel to and rests against themedial aspect of the index finger. This positioning of lower hand 20allows the lateral aspect of lower hand 20 to abut and rest against theanterior base of the thumb of upper hand 10, which assists the hands inworking together as a single unit. The DRP gripping technique positionsthe wrist of lower hand 20 in a more neutral position both at addressand at the time of impact. This allows the golfer to properly square theclub face of the golf club at impact with the ball on a more consistentbasis than is traditionally possible when utilizing the baseball stylemethod of gripping the club.

As indicated above, the present grip system consists of larger thannormal diameter golf grips. These oversized golf club grips are intendedto be used in conjunction with a modified method of gripping the grip,specifically, the DRP gripping method described in detail above.However, the oversized grips of the present invention may also be usedin conjunction with other gripping techniques, such as any of the threetraditional gripping methods and the baseball style gripping method, forexample. The grip diameters of the present system are enlarged by veryprecise amounts in order to replicate the circumference created whenusing traditional gripping methods, in which the lower hand grasps acorrectly sized standard golf grip and the thumb of the upper hand iscaptured by the fingers and palm of the lower hand.

In this manner, when used with the DRP gripping method, the oversizedgrips of the present invention duplicate the ideal cantilever armlengths formed between the axis of the golf club shaft and the centralaxis of the wrist of the golfer's lower hand, as described above. Thus,in order to form a golf club grip system that achieves the benefitsdescribed above, a grip system having, in one exemplary embodiment, fivedifferent grip sizes was developed. These grips may have a grip diametermeasured prior to being installed on a golf club shaft ranging from assmall as 25.0 mm, 25.2 mm, 25.5 mm, 25.7 mm, or 26.0 mm to as large as29.0 mm, 29.2 mm, 29.5 mm, 29.7 mm, or 30.0 mm. In one exemplaryembodiment, the golf grips range in grip diameters from 25.7 mm to 29.7mm prior to being installed on a golf club shaft. Installation of thegrips on the golf clubs causes the grips to expand by approximately 0.3mm in diameter. Thus, the grips may have resultant post-installationgrip diameters as small as 25.3 mm, 25.5 mm, 25.8 mm, 26.0 mm, or 26.3mm and as large as 29.3 mm, 29.5 mm, 29.8 mm, 30.0 mm, or 30.3 mm. Inone exemplary embodiment, the grips have resultant post-installationgrip diameters ranging from 26.0 mm to 30.0 mm.

By having a grip system that utilizes grip diameters within theabove-identified range, in conjunction with the lower hand placeddirectly on the grip without the thumb of the upper hand capturedbetween the grip and palm of the lower hand, the circumferences createdwhen golfers grip standard size golf grips with the thumb of the upperhand captured between the grip and the palm of the lower hand aresubstantially replicated. Additionally, in order to ensure that theproper cantilever arm lengths arc established, the total grip wallthicknesses of each of the grip sizes after installation on a golf clubshaft must be no thinner than substantially 5.6 mm and no thicker thansubstantially 7.6 mm, when standard golf shafts and standardinstallation techniques are used. Absent an indication to the contrary,as used herein, “grip wall thickness” refers to the thickness extendingradially between inner surface 103 of inner layer 110 and grippingsurface 13 of the outer wrap of a cross-section of a grip taken in adirection perpendicular to the longitudinal axis of the grip at adistance of about 158 mm from the proximal end of the golf grip definedby cap end 11, as depicted in FIG. 17. Additionally, by taking variousmeasurements of the golf grip, such as grip diameter and grip wallthickness, in the central portion of the golf club grip, such as at adistance of about 158 mm from the proximal end of a golf club griphaving a standard length gripping surface, the measurements are taken inan area of the golf grip that is grasped by the golfer during a golfswing and, as a result, has an effect on the resulting golf shot.

In one exemplary embodiment, this results in ratio ranges between thegrip diameter and the grip wall thickness at about 158 mm from theproximal end of the golf club grip defined by cap end 11, shown in FIG.16, in which the grip diameter must be no less than 3.8 times greaterthan the grip wall thickness and no more than 4.7 times greater than thegrip wall thickness. In another exemplary embodiment, ratio rangesbetween the grip diameter and the grip wall thickness at about 158 mmfrom the proximal end of the golf club grip defined by cap end 11 inwhich the grip diameter must be no less than 3.95 times greater than thegrip wall thickness and no more than 4.64 times greater than the gripwall thickness. Specific ratio ranges between the grip diameter and thegrip wall thickness for exemplary embodiments are set forth in Table 3below for both pre-installation grip diameters, i.e. before the grip isinstalled on a golf club shaft, and post-installation grip diameters.i.e. after the grip is installed on a golf club shaft.

TABLE 3 Grip Diameter to Grip Wall Thickness Ratios Ratio of Grip WallThickness Grip Diameter (in mm) to Grip Diameter 25.7 (pre-installation)1:4.64 26.0 (diameter of the 25.7 mm grip after 1:4.59 installation on astandard golf club shaft) 26.7 (pre-installation) 1:4.38 27.0 (diameterof the 26.7 mm grip after 1:4.43 installation on a standard golf clubshaft) 27.7 (pre-installation) 1:4.20 28.0 (diameter of the 27.7 mm gripafter 1:4.24 installation on a standard golf club shaft) 28.7(pre-installation) 1:4.04 29.0 (diameter of the 28.7 mm grip after1:4.08 installation on a standard golf club shaft) 29.7(pre-installation) 1:3.91 30 (diameter of the 29.7 mm grip after 1:3.95installation on a standard golf club shaft)

In order to confirm the advantages of the DRP gripping method,comparative testing between the baseball style gripping method and theDRP gripping method was performed, as set forth below in Example 3.Based on this testing, the golf shots executed with the baseball stylegripping method had an average golfer satisfaction score of 57.3, whilegolf shots executed with the DRP gripping method had an average golfersatisfaction score of 69.8. Additional comparative testing, the detailsof which are set forth below in Example 4, was performed to comparegolfer satisfaction scores obtained by using standard size golf gripsand the Vardon gripping method with golfer satisfaction scores obtainedby using oversized golf grips and the DRP gripping method. Based on thistesting, it was determined that golfers utilizing the standard sizegrips and the Vardon gripping method had an average golfer satisfactionscore of 46.1. In contrast, golfers using the oversized grips and theDRP gripping method had an average golfer satisfaction score of 69.8.

An additional advantage is provided by utilizing oversized grips and theDRP gripping method. Specifically, the total surface contact area thatthe lower hand has on the golf grip is increased, which influences theamount of rotational force that the lower hand and arm can apply to thegolf club during a golf swing. Placement of the hands on the standardgolf grip using any of the three traditional gripping methods, discussedin detail above, results in the golfer positioning the thumb of theupper hand between the grip and the fingers and palm of the lower hand.By moving the upper hand thumb from its traditional position, such as inthe manner described in detail above with reference to the DRP grippingmethod, a significant increase in the surface area of the finger andpalm of the lower hand that is in direct contact with the grip isachieved. This results in a greater rotational force that can be appliedto the grip by the lower hand and arm during the golf swing.

In order to determine the increase in the rotational force that could beapplied to a golf club utilizing the oversized grips of the presentinvention and the DRP gripping method, testing was performed using adial torque wrench. A first end of the dial torque wrench was mounted ina fixed position to a fixed floor mount. The opposing end of the dialtorque wrench had a handle that accepted a ¼ inch female socket drive.Two equivalent golf shafts having head ends with a ¼ inch male socketdrive permanently fixed to the shaft were alternatively engaged with the¼ inch female socket drive on the handle of the dial torque wrench. Onegolf shaft had a standard diameter golf grip. i.e., a golf grip having a21 mm grip diameter, and a standard gripping technique was used torotate the shaft. The second golf shaft had a 27.7 mm grip formed inaccordance with the present invention and the DRP gripping technique wasused to rotate the shaft. Golfers of various ages and ability turnedeach of the shafts as firmly as possible in a rotational direction inwhich the target would typically be located. Based on the testing,golfers were able to generate, on average, 38.7% more rotational forceusing the 27.7 mm grip and the DRP gripping method as opposed toutilizing the standard diameter golf grip with one of the threetraditional gripping methods.

Due to the added rotational force that a golfer can place on anoversized golf grip, as discussed in detail above, the torsion of thegrip must be low enough that rotation of the grip between the golf clubshaft and the golfer's hands does not significantly impact the golfshots. However, to provide a gripping surface that can be gripped by anarthritic golfer without causing pain and/or inflammation in thegolfer's hand while also providing an grip the allows the arthriticgolfer to produce the best golf shots possible, two competing concernsmust be balanced. Specifically, the elastic deformation of the grip,i.e., the ability of an arthritic golfer to compress and comfortablygrasp the grip in their hand, must be sufficient to prevent pain and/orinflammation. At the same time, the grip must be torsion resistantenough to prevent unnecessary rotation of the grip between the golf clubshaft and the golfer's hands.

Based on testing of elastic deformation, set forth below in Example 5,it was determined than an acceptable range of elastic deformation undera 5 pound compressive load would be at least 1.0 mm to no more than 2.0mm, while an acceptable range of elastic deformation under a 15 poundcompressive load would be at least 1.5 mm and no more than 3.0 mm. Asused herein, the phrase “elastic deformation” refers to the amount ofcompression experienced by a golf grip mounted on a golf shaft ascalculated using the method set forth below in Example 5. Additionally,based on the testing of grip torsion, set forth below in Example 6, itwas determined that the acceptable range of torsion that a golf gripshould experience between the golf shaft and the hands of a golfer is atleast 5.0 degrees and no more than 20.0 degrees. As used herein, thephrase “degree of torsion” refers to the amount of torsion that a golfgrip experiences as calculated using the method set forth in Example 6below. In forming the oversized grips of the present invention toprovide an elastic deformation and a range of torsion that are withinthe above-identified acceptable ranges, a series of individual layers ofmaterial are assembled to form a grip body. These layers are assembledso that each layer comprises a specific ratio of the overall thicknessof the golf club grip. These layer ratios, set forth in Tables 7 and 8and described below, significantly contribute to the benefits providedby the present golf club grip system.

Referring to FIGS. 15 and 16, the outer wrap of the grip provides thegolfer with a non-slip gripping surface and dampens impact shock andvibrations to provide the golfer with a grip that substantially lessensany pain and/or inflammation experienced when grasping the grip andstriking a golf ball. Thus, the outer wrap must be sufficiently thick toprovide the proper dampening effects, but also must be thin enough toprevent unnecessary twisting of the grip between the hands of the golferand the golf shaft during a golf swing. As a result, the outer wrapshould have low density and a medium to high deformation. For example,in one exemplary embodiment, the outer wrap has a Shore A hardness aslow as 10, 15, 20, or 25 Shore A hardness units and as high as 30, 35,40, or 45 Shore A hardness units. All Shore A hardness measurements setforth herein were achieved using ASTM Standard 2240, Standard TestMethod for Rubber Property-Durometer Hardness.

In one exemplary embodiment, the outer wrap is a combination of severaldifferent, individual layers of material that are secured together.Referring to FIGS. 15 and 16, in one exemplary embodiment, the outerwrap is formed from first polyurethane layer 100, felt layer 102, andsecond polyurethane layer 104, which are secured together, in part, byadhesive strip 106. Additionally, referring to Table 4 below, in oneexemplary embodiment, first polyurethane layer 100, felt layer 102, andsecond polyurethane layer 104 have thicknesses of 0.76 mm, 1.02 mm, and0.13 mm, respectively. In another exemplary embodiment, felt layer 102has a thickness of 0.52 mm.

TABLE 4 Thicknesses of Individual Components of the Outer Wrap Thicknessfor Pre- Thickness for Pre- Installation Grip Installation Grip Sizes27.7 mm, Sizes 25.7 mm 28.7 mm, Component of the Outer and 26.7 and 29.7mm Wrap mm (in mm) (in mm) Outer Polyethylene Layer 0.76 0.76 HighDensity Felt Layer 0.52 1.02 Adhesive Layer Between Felt 0.04 0.04 Layerand High Density Polyurethane Layer Inner High Density 0.13 0.13Polyurethane Layer Adhesive Layer Between 0.10 0.10 Inner PolyurethaneLayer and Inner Grip Layer (i.e., the underlisting) Total Thickness ofthe Outer 1.55 2.05 Wrap

In one exemplary embodiment, felt layer 102 is a sheet of material thatis formed from a natural fiber mat. For example, felt layer 102 may besubstantially similar to the felt layer used in X-Tack brand golf grips,commercially available from Karakal Golf Grips as product numberYZ-RD/SL-PUB. In one exemplary embodiment, the first step in forming thegolf grip is applying first polyurethane layer 100 to felt layer 102.Specifically, felt layer 102 is passed over the surface of a vat ofliquified, low density polyurethane to deposit first polyurethane layer100 thereon. In one exemplary embodiment, polyurethane layer 100 isformed from a polyurethane substantially similar to the polyurethaneused in Pro Soft™ Tennis Racquet Overgrips, commercially available fromWilson Tennis as product number WRZ4733.

Next, first polyurethane layer 100 and felt layer 102 are passed througha series of rollers to interdigitate the fibers of felt layer 102 into aportion of polyurethane layer 100. This bonds polyurethane layer 100 andfelt layer 102 together. Referring to Table 5 below, in one exemplaryembodiment, first, low density polyurethane layer 100 has a Shore Ahardness as low as 10, 15, or 20 Shore A harness units and as high as25, 30, or 35 Shore A hardness units. Shore A harness measurements forother layers of the grip are also set forth in Table 5.

TABLE 5 Durometer Shore A Hardness Scale Ratings for IndividualMaterials Used in the Construction of the Present Golf Grip and RelatedMaterials Measured in Accordance with ASTM Standard 2240 Material ShoreA Hardness Rating Outer Polyurethane Layer of the Outer Wrap 20 +/− 5Fiber Felt Layer of the Outer Wrap 45 +/− 5 Inner Polyurethane Layer ofthe Outer Wrap 72 +/− 5 Synthetic Rubber Inner Layer 70 +/− 5 Elatron Dbrand elastomer commercially 20 +/− 5 available from Elaston Kimya A.S.Prince Tennis Cushion Fit ™ brand tennis 20 +/− 5 racquet replacementgrip commerically available from Prince Sports, Inc., as part number UBS7H101020080

Once polyurethane layer 100 and felt layer 102 are secured together,adhesive strip 106 is applied to the undersurface of felt layer 102. Inone exemplary embodiment, adhesive strip 106 is a pressure sensitiveadhesive. In this embodiment, adhesive strip 106 includes a transparentpolyester intermediate layer with adhesive applied to opposing sides ofthe polyester intermediate layer. The construct is then passed through aseries of rollers to activate the adhesive and to interdigitate theadhesive with openings formed between the fibers of felt layer 102. Inone exemplary embodiment, adhesive strip 106 has a thickness of 0.04 mm.

Once adhesive strip 106 is adhered to felt layer 102, secondpolyurethane layer 104, which is formed from a high densitypolyurethane, is positioned adjacent adhesive strip 106 and passedthrough a series of pressure rollers to secure second polyurethane layer104 to felt layer 102 via adhesive strip 106. In one exemplaryembodiment, polyurethane layer 104 is formed from a polyurethanesubstantially similar to the polyurethane used in Series R MoldonRubber-Tired Wheels, commercially available from Hamilton Caster asproduct number W-820-R-3/4. Additionally, in one exemplary embodiment,second, high density polyurethane layer 104 has a Shore A hardness aslow as 55, 60, 65, or 70 Shore A hardness units and as high as 75, 80,85, or 90 Shore A hardness units. In one exemplary embodiment,polyurethane layer 104 has a Shore A harness of approximately 70 Shore Ahardness units.

Once first polyurethane layer 100, felt layer 102, second polyurethanelayer 104, and adhesive strip 106 are secured together, thin adhesivestrip 108 is applied to the underside of second polyurethane layer 104.In one exemplary embodiment, adhesive strip 106 and adhesive strip 108are substantially similar to the adhesive layers used in X-Tack brandgolf grips, commercially available from Karakal Golf Grips as productnumber YZ-RD/SL-PUB. In one exemplary embodiment, adhesive strip 108 hasa thickness of 0.10 mm. In one exemplary embodiment, the adhesive usedin adhesive strip 106 and adhesive strip 108 is a pressure sensitiveadhesive, i.e., an adhesive that forms a bond when a pressure is appliedto join the adhesive to the adherend. In this embodiment, once adhesivestrip 108 is applied to the underside of the outer wrap of the grip, theouter warp and adhesive strip 108 may be passed through a series ofrollers to activate adhesive strip 108. Additionally, the amount ofbonding of adhesive strip 106 and adhesive strip 108 to the adherend maybe controlled and/or modified by adjusting the amount of pressureapplied by the set of pressure rollers.

This construct, including first polyurethane layer 100, felt layer 102,adhesive strip 106, second polyurethane layer 104, and adhesive strip108 form the outer wrap of the grip. The outer wrap is then applied toinner layer 110, i.e., the underlisting, of the grip, which is the onlycomponent defining the inner grip layer. Specifically, the outer wrap isin the form of a strip that is secured to inner layer 110 by spiralwrapping the outer wrap around an outer surface of inner layer 110,which will form the inner core of the grip, in a known manner. In oneexemplary embodiment, the outer wrap is wrapped around inner layer 110manually. In another exemplary embodiment, the wrap construct is wrappedaround inner layer 110 using an automated process. A thin rubber nipple(not shown) on the end of inner layer 110, which is positioned nearestthe club head when installed on a golf club, is then folded over theterminal end of the wrap construct to secure the wrap construct to innerlayer 110 and to maintain the bond between the end of the outer wrap andinner layer 110. Additionally, irrespective of the method used toposition the outer wrap of the grip around inner layer 110, as the outerwrap is pulled taught and positioned around inner layer 110, the tensionon inner layer 110 and adhesive strip 108 work together to secure theouter wrap of the grip to inner layer 110.

In order to provide the golfer with a substantially firm inner surfacethat lessens any torsion of the grip during a golf swing, inner layer110 must be sufficiently thick to provide the proper torsion resistance,as identified above, while being thin enough to prevent any significantnegative impact on a golfer attempting to sufficiently grasp the golfgrip. As a result, inner layer 110 should be a substantially compressionand torque resistant layer with a medium to high tensile strength. Inone exemplary embodiment, inner layer 110 is formed as a thick, dense,synthetic rubber layer. For example, inner layer 110 may by formed froma synthetic rubber, such as ethylene propylene diene M-class rubber(“EPDM”). In one exemplary embodiment, the EPDM may have materialproperties substantially similar to the material properties of the EPDMused to form the 9 inch EPDM Tarp Strap, commercially available from AceHardware Corporation of Oak Brook, Ill., as product number 71282 havingthe Universal Product Code of 082901712824.

As discussed above and identified below in Tables 6 and 7 below,exemplary ratios between the inner layer thickness and the outer wrapthickness of the golf grip, significantly contribute to the benefitsprovided by the present golf grip system. As used herein, “outer wrapthickness” refers to the thickness of a cross-section of the outer wrap,i.e., the combined thickness of first polyurethane layer 100, felt layer102, adhesive strip 106, second polyurethane layer 104, and adhesivestrip 108, extending radially between an innermost surface defined bythe interior surface of adhesive strip 108 to a radially outermostsurface defined by the exterior surface of first polyurethane layer 100and taken in a direction perpendicular to the longitudinal axis of thegrip and measured at a distance of about 158 mm from the proximal end ofthe golf club grip defined by cap end 11, as shown in FIG. 17.

Similarly, absent an indication to the contrary, as used herein, “innerlayer thickness” refers to the thickness of a cross-section of the innerlayer, i.e., inner layer 110, extending radially between the innermostsurface of inner layer 110 defined by inner surface 103 and the radiallyoutermost surface of inner layer 110 and taken in a directionperpendicular to the longitudinal axis of the grip and measured at adistance of about 158 mm from the proximal end of the golf club gripdefined by cap end 11, which is depicted in FIG. 17. In one exemplaryembodiment, the inner grip thickness should be no less than 2.3 timesthicker than the outer wrap thickness and not more than 3.1 timesthicker than the outer wrap thickness. With reference to Table 6, in oneexemplary embodiment, the grip wall thickness should be no less than1.30 times thicker than the inner wall thickness and no more than 1.45times thicker than the inner wall thickness. Additionally, in oneexemplary embodiment, the grip wall thickness should be no less than 3.0times thicker than the outer wall thickness and no more than 4.1 timesgreater than the outer wall thickness.

TABLE 6 Inner Layer, Outer Wrap, and Total Grip Wall Thicknesses andRatios Ratio of Grip Total Inner Layer Diameter Grip Thickness Ratio ofthe Outer Pre- Inner Layer Outer Wrap Wall to the Total Wrap ThicknessInstallation Thickness Thickness Thickness Grip Wall to the Total Grip(in mm) (in mm) (in mm) (in mm) Thickness Wall Thickness 25.7 4.10 1.55.60 1:1.37 1:3.73 26.7 4.60 1.5 6.10 1:1.33 1:4.07 27.7 4.60 2.0 6.601:1.44 1:3.30 28.7 5.10 2.0 7.10 1:1.39 1:3.55 29.7 5.60 2.0 7.60 1:1.361:3.80

TABLE 7 Percentage of Total Grip Wall Thickness Defined by the OuterWrap and the Inner Layer Grip Diameter Percentage of the Percentage ofthe Ratio of the Pre- Total Grip Wall Total Grip Wall Inner LayerInstallation Thickness Formed Thickness Formed to the Outer (in mm) bythe Inner Layer by the Outer Wrapr Wrap 25.7 73.2 26.8 2.733:1 26.7 75.424.6 3.067:1 27.7 69.7 30.3 2.300:1 28.7 71.8 28.2 2.550:1 29.7 73.726.3 2.800:1

Once formed, in order to install a grip on the shaft of a golf club, theproper grip for the individual golfer, as determined in accordance withthe grip size recommendation chart of Table 1, is selected. Sincestandard golf shafts have a maximum diameter of 0.600 inches to 0.605inches, i.e. 15.24 mm to 15.37 mm, when a golf grip is installed on astandard golf shaft, the grip diameter is expanded. This expansion ofthe golf club grip averages approximately 0.10 inches, i.e., 0.3 mm, andis taken into account in the golf club grip size recommendation chart ofTable 1.

However, some golf clubs, such as drivers, fairway woods, and/or utilityclubs, have maximum golf shaft diameters that are larger than thestandard golf shaft diameter. For example, the golf shaft diameters maybe as large as 0.615 inches to 0.625 inches, i.e., 15.62 mm to 15.88 mm.These larger than standard golf shaft diameters cause greater thannormal expansion of the golf grip after it is installed on the golfclub, resulting in total golf grip expansion of 0.024 inches to 0.039inches, i.e., 0.6 mm to 1.0 mm. To compensate for the extra expansion ofthe grip by golf shafts having larger than standard golf shaftdiameters, a grip one size smaller than the size recommended by the golfgrip size recommendation chart of Table 1 may be used. This will correctfor the over expansion and result in the desired post-installation gripdiameter. In contrast, when golf shafts having golf shaft diameters thatare less than 0.595 inches, i.e., 15.113 mm, are used, the proximalportion of the shaft should be built up to the diameter of approximately0.600 inches, i.e., 15.24 mm, with the use of shaft build up tape. Theproper build up of undersized shafts helps ensure that the finalinstalled grip diameter is the proper diameter, as well as helps ensurethat the grip is properly affixed on the golf shaft before the shaft isused.

Once a golf club grip having the proper grip diameter is selected, alayer of golf grip tape with an adhesive on both sides is positioned onthe proximate end of the golf shaft. Depending on the type of adhesivethat is utilized on the golf grip tape, either a solvent or soapy wateris sprayed and/or poured over the tape. The golf grip is then promptlyslid over the taped golf shaft and placed in the desired position. Thenewly gripped golf club is then set aside until the necessaryevaporation and set-up times have elapsed. Once these times haveelapsed, the golf club is ready for use.

Additional adjustments involving the grip size and installation may needto be made if the golf club shaft contains parallel-sided proximalsections or if the shaft has a taper angle that is lower than a standardgolf shaft tapered angle. The use of either of these types of golfshafts causes greater than normal expansion to the middle and/or distalportions of the grip after it has been installed in golf clubs.

Utilizing the oversized grip system of the present invention, arthriticgolfers, with their associated reduced finger flexion and strength cancomfortably grasp the larger diameter grips and swing the golf clubwithout any reduction of the maximum club head velocity or optimal clubhead rotational rate. As a result, this grip system provides equal orsuperior protection from shock and vibration without the undesirableincrease in grip torsion of previous arthritic golf grips. Further, thedesign of the grip system helps to reduce the unavoidable loss of golfshot performance experience when utilizing oversized, arthritic grips.

EXAMPLES

The following non-limiting Examples illustrate various features andcharacteristics of the present invention, which is not to be construedas limited thereto.

Example 1 Preferred Increased Golf Grip Diameters for Individual Golfers

Over 75,000 golf shots were executed by amateur golfers ranging inindividual ability with United States Golf Association handicaps ofbetween 4 and 35. Each test golfer used a variety of golf clubs thatwere all fitted with oversized golf grips. Prototype oversized golfgrips were manufactured having grip diameters varying by 0.05 inches andhaving a minimum grip diameter of 1.0 inch and a maximum grip diameterof 1.5 inches. All measurements of the golf grip diameter were takenpost installation, i.e., after the grip had been properly installed on agolf club, and at a point on the grip 6.0 inches from junction J, shownin FIG. 16, defined by cap end 11 and gripping surface 13 of the golfgrip, in a similar manner as described in detail above. Additionally,each of the grips had a 0.60 inch standard grip size internal diameter.By utilizing golf grips having a maximum grip diameter of 1.50 inches,all of the grips were within the maximum legal dimensions allowed by theUnited States Golf Association, which require a grip diameter of lessthan 1.75 inches. Testing was also done with standard size golf gripsutilizing traditional grasping techniques.

In order to observe, score, collect, and record all test golf shots, thegolfer satisfaction scale, shown in Table 2 above, was used.Specifically, the golfer who performed the individual shot was asked toevaluate the shot and assign it a golfer satisfaction score based on the0 to 100 point golfer satisfaction scale, which is divided into onepoint increments. These results were recorded and tabulated. Each golferwas required to hit golf shots using all of the available grip sizes inthe series. Some test golfers preferred to grasp the oversized grips thesame way one would hold a baseball bat. However, most golfers held theoversized golf grips in a fashion that was part baseball like grip andpart traditional golf type grip.

Initial test results concluded that oversized grips with diametersranging from 1.00 inches to 1.20 inches produced the best golfersatisfaction scores, as shown in FIG. 18. Oversized golf grips withdiameters larger than 1.2 inches produced poor results and weretherefore eliminated from any further testing. Additionally, the initialtest series showed that within the 1.0 inch to 1.2 inch golf gripdiameter range, golfers with small hand sizes produced their best golfersatisfaction scores when using grips with small diameters, as shown inFIG. 19. Similarly, golfers with larger hand sizes produced their bestgolfer satisfaction scores when utilizing grips with larger diameters,as shown in FIGS. 20-23. Additionally, golfers that wore men's golfglove sizes small, large, and extra-extra large had the highest averagegolfer satisfaction scores, as shown in FIG. 24. Alternatively, as shownin FIG. 24, golfers that wore men's golf glove sizes of medium and extralarge had slightly lower average golfer satisfaction scores.

The initial test concluded that it was essential to properly match thesize of the oversized grips to the size of the golfer's hand to maximizegolf shot results. Additionally, it was also determined that prototypegrips should be manufactured having smaller diameter differences betweeneach grip size.

Example 2 Test Results Utilizing Three Different Diameters of OversizedGrips by Individual Golfers

The purpose of this testing was to determine the effects of variationsin golf grip diameter on in individual's golf shots. The grip sizerecommendation chart, as shown in Table 1 above, was used as a primarysizing reference for the test. Each individual golfer was required toperform three series of shots and there was a total of 50 shots in eachseries. The first series was conducted with the golfers utilizing a golfclub grip having the proper grip diameter as recommended by the gripsize recommendation chart of Table 1 above. The second series wasperformed with the golfers utilizing a grip having a grip diameter thatwas one size smaller than the grip size recommendation chart'srecommended grip diameter and the third series was performed withgolfers using a grip having a grip diameter that was one size largerthan the grip size recommendation chart's recommended grip diameter.Each shot was scored using the scoring system described in detail above.

Referring to FIG. 25, shots performed in the first series, i.e., theseries utilizing the grip diameter recommended by the grip sizerecommendation chart, had an average golfer satisfaction score of 70.2.In contrast, shots performed in the second series, i.e., the seriesutilizing a grip diameter that is one size smaller than the gripdiameter recommended by the grip size recommendation chart, produced anaverage golfer satisfaction score of 54.0. Similarly, shots from thethird series, i.e., the series utilizing a grip diameter that is onesize larger than the grip diameter recommended by the grip sizerecommendation chart, produced an average golfer satisfaction score of48.0. Thus, scores from the first series were 16.2 points higher thanscores from the second series, which represents a performance in thefirst series that was 30% better than the performance in the secondseries. Similarly, scores from the first series were 24.2 points higherthan scores from the third series, which represents the first seriesscores being 46% better than scores from the third series.

The resultant drop off in shot performance, as indicated by the golfersatisfaction score in the second and third series, was greater thanwould have been originally anticipated. The difference in the diameterbetween consecutive grip sizes recommended by the grip sizerecommendation chart are 0.03 inches, which is closely equivalent to thethickness of an average credit card. Deviation from the grip sizerecommendation chart by one grip size resulted in significantly reducedresults. Based on the results, this test validates the necessity toprovide an oversized grip system having several grip sizes withdiameters within a very specific diameter range. Each specific gripdiameter should be correctly matched to the size of an individualgolfer's hand in order for the oversized grip system to allow the golferto produce the highest quality of golf shots.

Example 3 Comparative Testing of the Baseball Style Grasping Method andthe DRP Grasping Method

In order to determine whether the DRP gripping method provided abeneficial improvement over the baseball style gripping method whenutilizing oversized golf club grips, testing was performed. During thetesting, each golfer used an oversized grip as recommended by the gripsize recommendation chart of Table 1 above. Each golfer was required tohit a minimum of 50 shots using the baseball style gripping method and50 shots using the DRP gripping method. All shots were scored by thegolfer using a golfer satisfaction score in a similar manner as setforth in detail above. The golfer satisfaction scores for each shot werethen recorded.

Referring to FIG. 26, golf shots executed using the baseball stylegrasping method had an average golfer satisfaction score of 57.3. Incontrast, golf shots executed using the DRP grasping method had anaverage golfer satisfaction score of 69.8.

Thus, the DRP grasping method had an average golfer satisfaction scorethat was 12.5 points higher than the average baseball style graspingmethod score. This resulted in a 22% improvement in shot quality andperformance. It is believed that the beneficial results occurred becausethe DRP grasping method allows for the wrist of the lower hand to passthrough the impact area in a more neutral position relative to thebaseball style gripping method and assists golfers in squaring the clubface at impact with a greater consistency. This allows a golfer toproperly square the club face at impact on a more consistent basis thanis possible using the baseball style gripping method of grasping a golfclub.

Example 4 Comparative Testing of Standard Size Golf Club Grips Utilizingthe Vardon Gripping Method versus the Oversized Golf Club Grip SystemUsing the DRP Gripping Method

This test was designed to compare golf shots made using standard gripdiameter golf club grips and the Vardon gripping method to golf shotsmade using oversized grip diameter golf club grips and the DRP grippingmethod. For each test, golfers were required to execute a minimum of 50shots using standard grip diameter golf club grips and the Vardongripping method and a minimum of 50 shots using oversized grip diametergrips and the DRP gripping method. After each golf shot, the individualgolfer rated the shot using a golfer satisfaction score system in themanner set forth in detail above.

Golf shots performed by golfers using standard grip diameter golf clubgrips and the Vardon gripping method resulted in an average golfersatisfaction score of 46.1. In contrast, golf shots performed with thegolfers using the oversized grip diameter grips and the DRP grippingmethod resulted in an average golfer satisfaction score of 69.8. Thus,oversized grip scores using the DRP gripping method were 23.7 pointshigher than golfer satisfaction scores using standard golf grips and theVardon gripping method. This equates to a 51.4% increase in golfersatisfaction, utilizing the DRP gripping method and oversized golfgrips.

Example 5 Golf Club Grip Elastic Deformation Testing

Testing was conducted to determine the elastic deformation of golf gripsmade in accordance with the present invention, as well as standard golfgrips. Each grip to be tested was installed on a True Temper® DYNAMICGOLD® golf shaft. True Temper® and DYNAMIC GOLD® are registeredtrademarks of True Temper Sports, Inc. of Memphis, Tenn. The grips wereinstalled on the golf shafts utilizing one layer of two inch wide griptape, commercially available as Product No. 902B from Golf Smith, Inc.Standard grip installation techniques were then utilized to secure thegrips in position. Once the grips were positioned and installed on theshafts, they were allowed to dry and set up for a minimum of 48 hours.

In order to measure the elastic deformation of each of the competinggrips, a compression vice system was designed and built. The compressionvice system utilizes a Jason Tools Electronic Digital Caliper, Model No.MT01013, commercially available from Jason International Trading Ltd. ofHong Kong. As shown in FIG. 27, digital caliper 200 includes upper andlower clamp jaws (not shown) that were rigidly secured to upper andlower jaw clamps 202, 204. Upper and lower jaw clamps 202, 204 areformed from ⅛^(th) inch by 0.75 inch aluminum bar stock having a widthof 0.52 inches that defined the contact surface for the golf club gripand shaft, as described below. Referring to FIG. 28, once upper andlower jaws of digital caliper 200 were secured to jaw clamps 202, 204,the lower jaw clamp 204 was positioned within bench top vice 206, asshown in FIG. 28, and vice 206 tightened, so that lower jaw clamp 204was fixed to bench vice 206.

Referring to FIGS. 28-31, platform 208, formed as a 5¾ inches by 5¾inches square, was configured to be placed atop upper jaw clamp 202.Platform 208 further included a 5½ inch piece of ⅜ inch channel trimaffixed to the bottom thereof by wood screws, nuts, and washers, asshown in dashed lines in FIG. 28. Centerline mark 210 (FIG. 29) wasformed in the channel trim to ensure that the platform could berepeatedly placed over upper jaw clamp 202 of digital caliper 200 toprovide a consistent downward vertical compressive load on the variousgolf grips being tested. Additionally, as shown in FIG. 28, on theopposing side of platform 208, circle 212 was made to ensure thatweights could be positioned at the exact center of platform 208.

Referring to FIG. 29, once properly positioned, golf club grip 214, thegrip to be tested, was placed in the opening between the upper and lowerclamp jaws 202, 204 fixed to digital caliper 200. Golf club grip 214 wasaligned so that a location spaced distance D, which was six inches fromjunction J defined between cap end 11 and gripping surface 13 of thegolf grip as shown in FIG. 29 or about 158 mm from the proximal end ofthe golf club grip defined by cap end 11, was centered on lower clampjaw 204 and the longitudinal axis of the grip was positionedperpendicular to the long axis of lower jaw clamp 204 of digital caliper200. Set screw 216, which securely locks slide 218 of digital caliper200 in position, was then loosened, allowing slide 218 to move freely.

Once in this position, wooden blocks 219, as shown in FIG. 30, wereplaced under club head end 220 of golf shaft 222 with the toe of theclub pointing down. Blocks 219 were sized so that shaft 222 waspositioned parallel to lower clamp jaw 204. With grip 214 positionedbetween upper and lower clamp jaws 202, 204, platform 208 was gentlylowered onto the top edge of upper clamp jaw 202 and caliper readingscale 224 was reset to 0.000 inches. As shown in FIGS. 30 and 31, two 2½pound weights 226 were lowered and centered on top of wooden platform208. Digital caliper 200 was than read and the amount of elasticdeformation of the grip, which corresponds to the reading displayed ondigital caliper 200, was recorded. Two 5 pound weights were then placedand centered on top of the two 2½ pound weights 226. Caliper readingscale 224 was than read and the amount of elastic deformation of thegrip recorded. The results of the testing are set forth below in Table8, which provides readings of elastic deformation on both the 5 lb. loadand the 15 lb. load, as described in detail above.

Based on the results as shown in Table 8, it was determined that a grip,in order to compress a reasonable amount under low hand pressure for anarthritic golfer while, at the same time, not over compressing whenfirmer hand pressure is applied, needs to elastically deform at least1.0 mm and no more than 2.0 mm under 5 lbs. of vertical compressiveforce. Similarly, under 15 lbs. of vertical compressive force, the gripshould deform no less than 1.5 mm and no more than 3.0 mm.

TABLE 8 Elastic Deformation of Golf Club Grips From VariousManufacturers Subjected To Vertical Compressive Loads 5 lb. Load 15 lb.Load Elastic Elastic Manufacturer Brand Grip Size DeformationDeformation Avon Chamois Jumbo 1.245 mm 2.286 mm Tacki-Mac Arthritic +3/32 in. 1.435 mm 2.360 mm Lamkin Perma-Wrap Standard 1.330 mm 1.880 mmWinn G 8 Standard 1.511 mm 2.030 mm Winn MasterWrap Standard 2.197 mm3.290 mm Golf Pride Full Cord Standard .9144 mm 1.322 mm Golf Pride DD 2Standard .9650 mm 1.400 mm Lamkin Crossline + 1/16 in. 1.143 mm 1.880 mmWinn Xi7 +⅛ in. 1.839 mm 2.590 mm Tour Edge Tour Edge Standard .9020 mm1.570 mm Lamkin Torsion Control +⅛ in. .8255 mm 1.397 mm Lamkin TorsionControl +⅛ in. .9144 mm 1.473 mm Tour Series Golf Club Grips Made in26.7 mm (pre- 1.230 mm 1.765 mm Accordance With an Exemplaryinstallation) Embodiment of the Present 27.7 mm (pre- 1.372 mm 2.110 mmInvention installation) 28.7 mm (pre- 1.816 mm 2.590 mm installation)

Example 6 Grip Torsion Testing Method and Apparatus

Testing was conducted to determine the torsion experienced by golf gripsmade in accordance with the present invention, as well as standard golfgrips. Each grip to be tested was installed on a True Temper® DYNAMICGOLD® golf shaft. True Temper® and DYNAMIC GOLD® are registeredtrademarks of True Temper Sports, Inc. of Memphis, Tenn. The grips wereinstalled on the golf shafts utilizing one layer of two inch wide griptape, commercially available as Product No. 902B from Golf Smith, Inc.Standard grip installation techniques were then utilized to secure thegrips in position. Once the grips were positioned and installed on theshafts, they were allowed to dry and set up for a minimum of 48 hours.

Referring to FIG. 32, each golf shaft was tested by first placing shaft300 within vinyl rubber vice clamp 302, commercially available fromGolfsmith as Product No. 913. Vinyl rubber vice clamp 302 is designedfor use with golf shafts 300 and includes an opening in the centerthereof having a substantially circular longitudinal cross-section thatconforms to the cross-section of shaft 300. The outer portions of rubbervice clamp 302 has substantially flat sides that provide for a largecontact area with bench mounted vice 304. Vinyl rubber vice clamp 302was positioned three inches from distal end 306 of grip 308. Proximalend 310 of grip 308 was secured by hose clamp 312, as shown in FIG.33-35, so that first edge 314 of clamp 312 was positioned directly overjunction J defined between cap end 11 and gripping surface 13 of grip308. Hose clamp 312 was tightened around proximal end 310 of grip 308with flat head screwdriver 316, as shown in FIG. 33.

Referring to FIG. 34, wood blocks 318 were then placed under proximalend 310 of grip 308 and an aperture was drilled through side bracket 320of hose clamp 312 and into wood block 318. Drill chuck 322 was thenloosened and the drill removed from drill bit 324, allowing drill bit324 to function as a securement mechanism for retaining hose clamp 312in position relative to wood block 318. The top surface of grip 308 wasthen placed in a horizontally level position and the position confirmedusing pitch angle level 326, as shown in FIG. 36. Referring to FIG. 35,in order to provide additional fixation to proximal end 310 of grip 308,square washer 328 was placed over proximal end 310 of grip 308 and screw330 inserted through an aperture in square washer 328. Screw 330 wasthen advanced into wooden block 318 to tighten square washer 328 againstproximal end 310 of grip 308.

In order to ensure that wooden block 318 remained rigidly fixed atopwork bench 332, shown in FIG. 35, mini bar clamp or spreader 334, suchas Craftsman mini bar clamp/spreader, commercially available fromCraftsman as Part No. 31669, was used to clamp wood block 318 toworkbench 332. Strap wrench 336, shown in FIG. 37, was then placedaround grip 308 at a location perpendicular to the long axis of grip 308and spaced three inches from junction J defined between cap end 11 andgripping surface 13 or about 82 mm from the proximal end of the golfclub grip defined by cap end 11. In this position, strap wrench 336could be actuated in the direction of arrow A of FIG. 37 to torque grip308 in an upward direction. Referring to FIG. 38, spring scale 338 wasthen connected to torque grip 308 at a distance of 150 mm from the outersurface, i.e., gripping surface 13, of the grip by placing grabbing hook340 through aperture 342 in wrench handle 344. Referring to FIG. 39, anupward force was then applied to spring scale 338 in the direction ofarrow B until 5 lbs. of force registered on spring scale 338 and strapwrench handle 344 was in a horizontal position.

Wood block 346 was then placed between handle 344 of strap wrench 336and the top of work bench 332 to hold strap wrench handle 344 in asubstantially horizontal position. The spring scale was then removed.Second strap wrench 348 was placed around grip 308 at a location sixinches from junction J defined by cap end 11 and gripping surface 13, asshown in FIG. 40, or about 158 mm from the proximal end of the gripdefined by cap end 11. With strap wrench 348 in this position, strapwrench 348 could be actuated to apply torque in a downward direction,i.e., the direction of arrow C. Additionally, a section of brass tubing350 was cut to 8.25 inches and secured to strap wrench 348 with ducttape 352.

Referring to FIG. 41, 18 inch long bungee cord 354 was hooked through anopening in strap wrench 348 at a distance of 150 mm from the outersurface, i.e., gripping surface 13, of the grip. A strip of super heavyduty duct tape was wrapped around the opening in strap wrench 348 tokeep hook 356 of bungee cord 354 in the outermost position of theopening, i.e. to keep hook 356 of bungee cord 354 spaced a distance of150 mm from the gripping surface 13 of the grip. Strap wrench 348 waspreloaded by hooking a ½ lb. rubber mallet 358 onto the lower bungeecord hook, as shown in FIG. 41. Brass tubing 350 was than positioned sothat it rested at a 45 degree angle midway between a vertical and ahorizontal plane. The 45 degree angle position of the brass tubing waschecked and validated utilizing pitch angle level 326.

The initial position of the tip of brass tubing 350 was measuredutilizing a carpenter's aluminum ruler 360. Constant downward tensionwas kept on bungee cord 354 and ½ lb. rubber mallet 358 was removed fromthe lower bungee cord hook. 2½ lb. rubber mallet (not shown) was thenhung on the lower bungee cord hook. Aluminum ruler 360 was used tomeasure the location of the tip of brass tubing 350 as the handle ofstrap wrench 348 rotated under the gravitational force caused by the 2½lb. rubber mallet.

The measurement of the distance that the tip of brass tubing 350 movedwhen the 2½ lb. rubber mallet was hung on the lower hook of bungee cord354 was utilized to calculate the length of the arch over which the tipof brass tube 350 moved as wrench 348 was rotated. The length from themid-line of grip 308 to the tip of brass tubing 350 formed the radius ofthe arc and was used to calculate the circumference of a circle that thetip of brass tube 350 would travel if actuated 360 degrees. These twomeasurements were used to calculate the number of degrees of torsion ofthe grip experience between the three inch and six inch positions, i.e.,strap wrench 336 and strap wrench 348, on grip 308. The pitch anglelevel was used to cross-check and validate all grip torsionmeasurements.

The three inch and six inch positions selected for placement of strapwrenches 336, 348 were approximately positioned at the mid-line of theupper and lower hands when a golfer gripped the golf grip. This gives areasonable approximation of the amount of torsion the golfer willexperience between the shaft and the outer surface of the grip during agolf swing. Thus, if a golfer strikes the ball outside the affectivesweet spot of the club face, the moment arm created between the longaxis of the shaft and the point of impact with the club face with theball will be lengthened and the grip will twist a greater amount. Gripswith less resistance to torsion will be more negatively affected on theoff center shots than grips with good torsion resistance.

The results of the torsion testing, set forth below in Table 9 below,indicated that golf grips should experience a minimum torsion of 5.0degrees and a maximum torsion of 20.0 degrees. Additionally, in somegrip designs, the maximum level torsion may be as low as 19.5, 19.0,18.5, 18.0, or 17.5 degrees.

TABLE 9 Torsion Testing of Golf Grips Manufacturing According to anExemplary Embodiment of the Present Invention and of CommerciallyAvailable Standard, Mid-Size, Over-Size, and Arthritic Golf GripsManufacturer Grip Size Brand/Style Torsion Lamkin Standard Perma-WrapPlus 28.26 Degrees Golfpride Standard Dual Durometer 2 27.40 DegreesTour Edge Standard Tour Edge 50.62 Degrees Winn Standard G8 12.17Degrees Golfpride Standard Tour Wrap-Full 10.20 Degrees Cord LamkinMidsize + 1/16 Crossline 25.03 Degrees Winn Oversize +⅛ Xi7 21.03Degrees Lamkin Oversize +⅛ Torsion Control 26.11 Degrees Lamkin Oversize+⅛ Torsion Control 27.67 Degrees “Tour Series” Chamois +⅛ Arthritic50.27 Degrees Tacki-Mac + 3/32 Arthritic 49.89 Degrees Grip Made in 26.7mm Medium 13.60 Degrees Accordance with an Exemplary Embodiment of thePresent Invention Grip Made in 27.7 mm Medium/Large 14.87 DegreesAccordance with an Exemplary Embodiment of the Present Invention GripMade in 28.7 mm Large 10.44 Degrees Accordance with an ExemplaryEmbodiment of the Present Invention

While this invention has been described as having a preferred design,the present invention can be further modified within the spirit andscope of this disclosure. This application is therefore intended tocover any variations, uses, or adaptations of the invention using itsgeneral principles. Further, this application is intended to cover suchdepartures from the present disclosure as come within known or customarypractice in the art to which this invention pertains and which fallwithin the limits of the appended claims.

1. A golf club grip system, comprising: a plurality of golf club grips,each of said plurality of golf club grips having an inner layer and anouter wrap, said inner layer forming a substantially cylindrical bodyhaving an open end for receipt of a golf club shaft and a cap end, saidouter wrap surrounding at least a portion of said inner layer anddefining a gripping surface, each of said plurality of golf club gripshaving a grip diameter prior to installation on a golf club shaftdefined by said gripping surface and a grip wall thickness extendingradially from an inner surface of said inner layer to said grippingsurface, both of said grip diameter and said grip wall thicknessmeasured at a distance of about 158 millimeters from a proximal end ofeach of said plurality of golf club grips defined by said cap end ofeach of said plurality of golf club grips, said grip diameter being atleast 3.8 times greater than said grip wall thickness and no more than4.7 times greater than said grip wall thickness.
 2. The golf club gripsystem of claim 1, wherein said grip diameter of each of said pluralityof golf club grips measured prior to installation on a golf club shaftis at least 25.4 millimeters and no more than 30.5 millimeters.
 3. Thegolf club grip system of claim 1, wherein said plurality of golf clubgrips includes a first golf club grip having a first grip diametermeasured prior to installation on a golf club shaft of substantially25.7 millimeters, a second golf club grip having a second grip diametermeasured prior to installation on a golf club shaft of substantially26.7 millimeters, a third golf club grip having a third grip diametermeasured prior to installation on a golf club shaft of substantially27.7 millimeters, and a fourth golf club grip having a fourth gripdiameter measured prior to installation on a golf club shaft ofsubstantially 28.7 millimeters.
 4. The golf club grip system of claim 1,wherein each of said plurality of golf club grips has a degree oftorsion of at least five degrees and no more than twenty degrees. 5.(canceled)
 6. The golf club grip system of claim 1, wherein each of saidplurality of golf club grips includes an inner layer having an innerlayer thickness and an outer wrap having an outer wrap thickness, bothof said inner layer thickness and said outer wrap thickness measured ata distance of about 158 millimeters from a proximal end of each of saidplurality of golf club grips defined by said cap end of each of saidplurality of golf club grips, the sum of said inner layer thickness andsaid outer wrap thickness defining said grip wall thickness, whereinsaid inner layer thickness is at least 2.3 times greater than said outerwrap thickness and said inner layer thickness is no more than 3.1 timesgreater than said outer wrap thickness.
 7. The golf club grip system ofclaim 6, wherein said inner layer thickness of each of said plurality ofgolf club grips is at least 2.7 times greater than said outer wrapthickness of each of said plurality of golf club grips.
 8. The golf clubgrip system of claim 6, wherein said grip wall thickness of each of saidplurality of golf club grips is no less than 1.30 times greater thansaid inner layer thickness of each of said plurality of golf club gripsand said grip wall thickness of each of said plurality of golf clubgrips is no more than 1.45 times greater than said inner layer thicknessof each of said plurality of golf club grips.
 9. The golf club gripsystem of claim 6, wherein said outer wrap thickness of each of saidplurality of golf club grips is at least 1.5 millimeters and no morethan 2.1 millimeters.
 10. A golf club grip system, comprising: aplurality of golf club grips, each of the plurality of golf club gripscomprising: an inner layer forming a substantially cylindrical bodyhaving an open end for receipt of a golf club shaft and a cap end, saidinner layer having an inner layer thickness measured prior toinstallation on a golf club shaft; and an outer wrap surrounding atleast a portion of said inner layer and defining a gripping surface,said outer wrap having an outer wrap thickness measured prior toinstallation on a golf club shaft, said outer wrap including a firstpolymer layer secured to a first side of a felt layer, a first adhesivepositioned on a second side of said felt layer, and a second polymerlayer secured to said second side of said felt layer by said adhesive,wherein said inner layer thickness is at least 2.3 times greater thansaid outer wrap thickness and no more than 3.1 times greater than saidouter wrap thickness when measured at a distance of about 158millimeters from a proximal end of each of said plurality of golf clubgrips defined by said cap end of each of said plurality of golf clubgrips.
 11. The golf club grip system of claim 10, wherein said outerwrap of each of said plurality of golf club grips further comprises asecond adhesive, wherein said outer wrap is secured to said inner layerby said second adhesive.
 12. The golf club grip system of claim 10,wherein said inner layer thickness of each of said plurality of golfclub grips is at least 2.7 times greater than said outer wrap thicknessof each of said plurality of golf club grips when measured at a distanceof about 158 millimeters from a proximal end of each of said pluralityof golf club grips defined by said cap end of each of said plurality ofgolf club grips.
 13. The golf club grip system of claim 12, wherein eachof said plurality of golf club grips further comprise a grip wallthickness equal to a sum of said inner layer thickness and said outerwrap thickness, said grip wall thickness of each of said plurality ofgolf club grips being no more than 1.45 times greater than said innerlayer thickness of each of said plurality of golf club grips and saidgrip wall thickness of each of said plurality of golf club grips beingno less than 1.30 times greater than said inner layer thickness of eachof said plurality of golf club grips when measured at a distance ofabout 158 millimeters from a proximal end of each of said plurality ofgolf club grips defined by said cap end of each of said plurality ofgolf club grips.
 14. The golf club grip system of claim 10, wherein eachof said plurality of golf club grips has a degree of torsion of at leastfive degrees and no more than twenty degrees.
 15. (canceled)
 16. Thegolf club grip system of claim 10, wherein said outer wrap thickness ofeach of said plurality of golf club grips is at least 1.5 millimetersand no more than 2.1 millimeters. 17-20. (canceled)